I've just tried WD40 and it didn't touch it. It doesn't harm the varnish, but doesn't touch the line. It's like the pigment has been sucked into the varnish. I think it would need something like bleach which I'm sure would damage the varnish.
thanks for so bravely testing your white desk savoy, I hope she doesn't develop any bad habits! haven't seen that orange product over here unfortunately
Try some bread - i have used that in the past when didn't have a magic eraser and it works. At least it won't do any harm!
Or try rubbing gently with a microfibre cloth, might need to dampen it slightly. Again, shouldn't do any harm.
Are loads of other things you can try (WD40, lemon juice, washing powder, hairspray, dry wipe pen etc) but how they react to the varnish is the question.
The dry wipe pen works on permanent marker stains - you write over the mark with drywipe pen and rub off straight away - the solvent in the drywipe ink dissolves the permanent ink and you can wipe off. This has worked for me brilliantly in the past.
Well, despite warning on soda crystals packet about not letting them anywhere near varnished or lacquered surfaces, they don't seem to damage this varnish. I used some dissolved on some cotton wool on the stains and there was a faint blue mark appeared on the cotton wool, so it did seem to be making some impact. I'm still a bit scared about what else they might do though.
MousseCake, thanks for all those suggestions.
I just tried some bread, since i actually have some here for a change, and that too seems to be having an effect.
i've now got only very faint lines and I'll persevere when my fingers recover so thanks all!